Electronic components and circuits are known in which a substrate or carrier contains a circuit or array of electrical elements and a plurality of contact areas or leads by which electrical connection is made to the component. The substrate is usually a ceramic plate on one surface of which the circuit elements and interconnecting paths are formed. The contact areas, for a leadless package, are provided on the opposite substrate surface, or, for a leaded package, leads or pins extend from the substrate surface. The package can contain a large number of contact areas or leads which typically can be of the order of 120 to 180 contacts or leads.
A socket for retaining a leadless component conventionally includes an array of leaf-type spring contacts, each of which is matable with a respective contact area of the package. The component is installed on the leaf springs of the socket and retained in position by a clamp or latch mechanism. Such leaf spring sockets have certain disadvantages, especially where a large number of contacts are employed. The leaf springs occupy a relatively large amount of space on the socket and thereby limit the number of contacts which can be provided. In addition, solder or flux on the lead of the leaf contact can flow onto the contact and cause contamination of the contact.
A conventional socket for a multi-pin leaded component includes an array of socket openings, each for acceptance of a respective pin. The insertion and removal forces on the component are a function of the number of pins of the component, and such forces can be very high for a component having a large number of pins, such as a 120 to 180 pin package. Moreover, the socket openings are configured to tightly engage the lead pins, and the close tolerances between the pin dimensions and socket contact dimensions require careful alignment of the pins when inserting a component. Misalignment of any of the package pins can hamper or prevent component insertion.
Spring loaded test probes are employed in sockets or fixtures which are part of automatic electronic test systems used for the testing of electronic circuits. The test fixture is composed of an array of spring probes arranged in a row-and-column array known as a "bed of nails." The probe tips are of a configuration to contact the contact area or lead of a circuit to be tested, and the terminals of those probes which are in contact with the particular circuit under test are connected to the test system. These spring probes are relatively large and of elaborate construction, and are designed to be repeatedly loaded and unloaded as circuits are installed and removed for testing, and thus are relatively expensive and are not of a construction or cost practical for a component socket.